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  <div class="section" id="trackback-class">
<h1>Trackback Class<a class="headerlink" href="#trackback-class" title="Permalink to this headline">¶</a></h1>
<p>The Trackback Class provides functions that enable you to send and
receive Trackback data.</p>
<p>If you are not familiar with Trackbacks you&#8217;ll find more information
<a class="reference external" href="http://en.wikipedia.org/wiki/Trackback">here</a>.</p>
<div class="contents local topic" id="contents">
<ul class="simple">
<li><a class="reference internal" href="#using-the-trackback-class" id="id1">Using the Trackback Class</a><ul>
<li><a class="reference internal" href="#initializing-the-class" id="id2">Initializing the Class</a></li>
<li><a class="reference internal" href="#sending-trackbacks" id="id3">Sending Trackbacks</a></li>
<li><a class="reference internal" href="#receiving-trackbacks" id="id4">Receiving Trackbacks</a></li>
<li><a class="reference internal" href="#your-ping-url" id="id5">Your Ping URL</a></li>
<li><a class="reference internal" href="#creating-a-trackback-table" id="id6">Creating a Trackback Table</a></li>
<li><a class="reference internal" href="#processing-a-trackback" id="id7">Processing a Trackback</a><ul>
<li><a class="reference internal" href="#notes" id="id8">Notes:</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#class-reference" id="id9">Class Reference</a></li>
</ul>
</div>
<div class="custom-index container"></div><div class="section" id="using-the-trackback-class">
<h2><a class="toc-backref" href="#id1">Using the Trackback Class</a><a class="headerlink" href="#using-the-trackback-class" title="Permalink to this headline">¶</a></h2>
<div class="section" id="initializing-the-class">
<h3><a class="toc-backref" href="#id2">Initializing the Class</a><a class="headerlink" href="#initializing-the-class" title="Permalink to this headline">¶</a></h3>
<p>Like most other classes in CodeIgniter, the Trackback class is
initialized in your controller using the <tt class="docutils literal"><span class="pre">$this-&gt;load-&gt;library()</span></tt> method:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">library</span><span class="p">(</span><span class="s1">&#39;trackback&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>Once loaded, the Trackback library object will be available using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span>
</pre></div>
</div>
</div>
<div class="section" id="sending-trackbacks">
<h3><a class="toc-backref" href="#id3">Sending Trackbacks</a><a class="headerlink" href="#sending-trackbacks" title="Permalink to this headline">¶</a></h3>
<p>A Trackback can be sent from any of your controller functions using code
similar to this example:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">library</span><span class="p">(</span><span class="s1">&#39;trackback&#39;</span><span class="p">);</span>

<span class="nv">$tb_data</span> <span class="o">=</span> <span class="k">array</span><span class="p">(</span>
        <span class="s1">&#39;ping_url&#39;</span>  <span class="o">=&gt;</span> <span class="s1">&#39;http://example.com/trackback/456&#39;</span><span class="p">,</span>
        <span class="s1">&#39;url&#39;</span>       <span class="o">=&gt;</span> <span class="s1">&#39;http://www.my-example.com/blog/entry/123&#39;</span><span class="p">,</span>
        <span class="s1">&#39;title&#39;</span>     <span class="o">=&gt;</span> <span class="s1">&#39;The Title of My Entry&#39;</span><span class="p">,</span>
        <span class="s1">&#39;excerpt&#39;</span>   <span class="o">=&gt;</span> <span class="s1">&#39;The entry content.&#39;</span><span class="p">,</span>
        <span class="s1">&#39;blog_name&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;My Blog Name&#39;</span><span class="p">,</span>
        <span class="s1">&#39;charset&#39;</span>   <span class="o">=&gt;</span> <span class="s1">&#39;utf-8&#39;</span>
<span class="p">);</span>

<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">send</span><span class="p">(</span><span class="nv">$tb_data</span><span class="p">))</span>
<span class="p">{</span>
        <span class="k">echo</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">display_errors</span><span class="p">();</span>
<span class="p">}</span>
<span class="k">else</span>
<span class="p">{</span>
        <span class="k">echo</span> <span class="s1">&#39;Trackback was sent!&#39;</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>Description of array data:</p>
<ul class="simple">
<li><strong>ping_url</strong> - The URL of the site you are sending the Trackback to.
You can send Trackbacks to multiple URLs by separating each URL with a comma.</li>
<li><strong>url</strong> - The URL to YOUR site where the weblog entry can be seen.</li>
<li><strong>title</strong> - The title of your weblog entry.</li>
<li><strong>excerpt</strong> - The content of your weblog entry.</li>
<li><strong>blog_name</strong> - The name of your weblog.</li>
<li><strong>charset</strong> - The character encoding your weblog is written in. If omitted, UTF-8 will be used.</li>
</ul>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The Trackback class will automatically send only the first 500 characters of your
entry. It will also strip all HTML.</p>
</div>
<p>The Trackback sending method returns TRUE/FALSE (boolean) on success
or failure. If it fails, you can retrieve the error message using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">display_errors</span><span class="p">();</span>
</pre></div>
</div>
</div>
<div class="section" id="receiving-trackbacks">
<h3><a class="toc-backref" href="#id4">Receiving Trackbacks</a><a class="headerlink" href="#receiving-trackbacks" title="Permalink to this headline">¶</a></h3>
<p>Before you can receive Trackbacks you must create a weblog. If you don&#8217;t
have a blog yet there&#8217;s no point in continuing.</p>
<p>Receiving Trackbacks is a little more complex than sending them, only
because you will need a database table in which to store them, and you
will need to validate the incoming trackback data. You are encouraged to
implement a thorough validation process to guard against spam and
duplicate data. You may also want to limit the number of Trackbacks you
allow from a particular IP within a given span of time to further
curtail spam. The process of receiving a Trackback is quite simple; the
validation is what takes most of the effort.</p>
</div>
<div class="section" id="your-ping-url">
<h3><a class="toc-backref" href="#id5">Your Ping URL</a><a class="headerlink" href="#your-ping-url" title="Permalink to this headline">¶</a></h3>
<p>In order to accept Trackbacks you must display a Trackback URL next to
each one of your weblog entries. This will be the URL that people will
use to send you Trackbacks (we will refer to this as your &#8220;Ping URL&#8221;).</p>
<p>Your Ping URL must point to a controller function where your Trackback
receiving code is located, and the URL must contain the ID number for
each particular entry, so that when the Trackback is received you&#8217;ll be
able to associate it with a particular entry.</p>
<p>For example, if your controller class is called Trackback, and the
receiving function is called receive, your Ping URLs will look something
like this:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">http</span><span class="o">://</span><span class="nx">example</span><span class="o">.</span><span class="nx">com</span><span class="o">/</span><span class="nx">index</span><span class="o">.</span><span class="nx">php</span><span class="o">/</span><span class="nx">trackback</span><span class="o">/</span><span class="nx">receive</span><span class="o">/</span><span class="nx">entry_id</span>
</pre></div>
</div>
<p>Where entry_id represents the individual ID number for each of your
entries.</p>
</div>
<div class="section" id="creating-a-trackback-table">
<h3><a class="toc-backref" href="#id6">Creating a Trackback Table</a><a class="headerlink" href="#creating-a-trackback-table" title="Permalink to this headline">¶</a></h3>
<p>Before you can receive Trackbacks you must create a table in which to
store them. Here is a basic prototype for such a table:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">CREATE</span> <span class="nx">TABLE</span> <span class="nx">trackbacks</span> <span class="p">(</span>
        <span class="nx">tb_id</span> <span class="nx">int</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="nx">unsigned</span> <span class="k">NOT</span> <span class="k">NULL</span> <span class="nx">auto_increment</span><span class="p">,</span>
        <span class="nx">entry_id</span> <span class="nx">int</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="nx">unsigned</span> <span class="k">NOT</span> <span class="k">NULL</span> <span class="k">default</span> <span class="mi">0</span><span class="p">,</span>
        <span class="nx">url</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">200</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
        <span class="nx">title</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">100</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
        <span class="nx">excerpt</span> <span class="nx">text</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
        <span class="nx">blog_name</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">100</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
        <span class="nx">tb_date</span> <span class="nx">int</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
        <span class="nx">ip_address</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">45</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
        <span class="nx">PRIMARY</span> <span class="nx">KEY</span> <span class="sb">`tb_id`</span> <span class="p">(</span><span class="sb">`tb_id`</span><span class="p">),</span>
        <span class="nx">KEY</span> <span class="sb">`entry_id`</span> <span class="p">(</span><span class="sb">`entry_id`</span><span class="p">)</span>
<span class="p">);</span>
</pre></div>
</div>
<p>The Trackback specification only requires four pieces of information to
be sent in a Trackback (url, title, excerpt, blog_name), but to make
the data more useful we&#8217;ve added a few more fields in the above table
schema (date, IP address, etc.).</p>
</div>
<div class="section" id="processing-a-trackback">
<h3><a class="toc-backref" href="#id7">Processing a Trackback</a><a class="headerlink" href="#processing-a-trackback" title="Permalink to this headline">¶</a></h3>
<p>Here is an example showing how you will receive and process a Trackback.
The following code is intended for use within the controller function
where you expect to receive Trackbacks.:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">library</span><span class="p">(</span><span class="s1">&#39;trackback&#39;</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">database</span><span class="p">();</span>

<span class="k">if</span> <span class="p">(</span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">uri</span><span class="o">-&gt;</span><span class="na">segment</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span> <span class="o">==</span> <span class="k">FALSE</span><span class="p">)</span>
<span class="p">{</span>
        <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">send_error</span><span class="p">(</span><span class="s1">&#39;Unable to determine the entry ID&#39;</span><span class="p">);</span>
<span class="p">}</span>

<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">receive</span><span class="p">())</span>
<span class="p">{</span>
        <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">send_error</span><span class="p">(</span><span class="s1">&#39;The Trackback did not contain valid data&#39;</span><span class="p">);</span>
<span class="p">}</span>

<span class="nv">$data</span> <span class="o">=</span> <span class="k">array</span><span class="p">(</span>
        <span class="s1">&#39;tb_id&#39;</span>      <span class="o">=&gt;</span> <span class="s1">&#39;&#39;</span><span class="p">,</span>
        <span class="s1">&#39;entry_id&#39;</span>   <span class="o">=&gt;</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">uri</span><span class="o">-&gt;</span><span class="na">segment</span><span class="p">(</span><span class="mi">3</span><span class="p">),</span>
        <span class="s1">&#39;url&#39;</span>        <span class="o">=&gt;</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">data</span><span class="p">(</span><span class="s1">&#39;url&#39;</span><span class="p">),</span>
        <span class="s1">&#39;title&#39;</span>      <span class="o">=&gt;</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">data</span><span class="p">(</span><span class="s1">&#39;title&#39;</span><span class="p">),</span>
        <span class="s1">&#39;excerpt&#39;</span>    <span class="o">=&gt;</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">data</span><span class="p">(</span><span class="s1">&#39;excerpt&#39;</span><span class="p">),</span>
        <span class="s1">&#39;blog_name&#39;</span>  <span class="o">=&gt;</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">data</span><span class="p">(</span><span class="s1">&#39;blog_name&#39;</span><span class="p">),</span>
        <span class="s1">&#39;tb_date&#39;</span>    <span class="o">=&gt;</span> <span class="nb">time</span><span class="p">(),</span>
        <span class="s1">&#39;ip_address&#39;</span> <span class="o">=&gt;</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">input</span><span class="o">-&gt;</span><span class="na">ip_address</span><span class="p">()</span>
<span class="p">);</span>

<span class="nv">$sql</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">db</span><span class="o">-&gt;</span><span class="na">insert_string</span><span class="p">(</span><span class="s1">&#39;trackbacks&#39;</span><span class="p">,</span> <span class="nv">$data</span><span class="p">);</span>
<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">db</span><span class="o">-&gt;</span><span class="na">query</span><span class="p">(</span><span class="nv">$sql</span><span class="p">);</span>

<span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">send_success</span><span class="p">();</span>
</pre></div>
</div>
<div class="section" id="notes">
<h4><a class="toc-backref" href="#id8">Notes:</a><a class="headerlink" href="#notes" title="Permalink to this headline">¶</a></h4>
<p>The entry ID number is expected in the third segment of your URL. This
is based on the URI example we gave earlier:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">http</span><span class="o">://</span><span class="nx">example</span><span class="o">.</span><span class="nx">com</span><span class="o">/</span><span class="nx">index</span><span class="o">.</span><span class="nx">php</span><span class="o">/</span><span class="nx">trackback</span><span class="o">/</span><span class="nx">receive</span><span class="o">/</span><span class="nx">entry_id</span>
</pre></div>
</div>
<p>Notice the entry_id is in the third URI segment, which you can retrieve
using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">uri</span><span class="o">-&gt;</span><span class="na">segment</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span>
</pre></div>
</div>
<p>In our Trackback receiving code above, if the third segment is missing,
we will issue an error. Without a valid entry ID, there&#8217;s no reason to
continue.</p>
<p>The $this-&gt;trackback-&gt;receive() function is simply a validation function
that looks at the incoming data and makes sure it contains the four
pieces of data that are required (url, title, excerpt, blog_name). It
returns TRUE on success and FALSE on failure. If it fails you will issue
an error message.</p>
<p>The incoming Trackback data can be retrieved using this function:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">data</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">)</span>
</pre></div>
</div>
<p>Where item represents one of these four pieces of info: url, title,
excerpt, or blog_name</p>
<p>If the Trackback data is successfully received, you will issue a success
message using:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">trackback</span><span class="o">-&gt;</span><span class="na">send_success</span><span class="p">();</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The above code contains no data validation, which you are
encouraged to add.</p>
</div>
</div>
</div>
</div>
<div class="section" id="class-reference">
<h2><a class="toc-backref" href="#id9">Class Reference</a><a class="headerlink" href="#class-reference" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="CI_Trackback">
<em class="property">class </em><tt class="descname">CI_Trackback</tt><a class="headerlink" href="#CI_Trackback" title="Permalink to this definition">¶</a></dt>
<dd><dl class="attribute">
<dt>
<tt class="descname">$data = array('url' =&gt; '', 'title' =&gt; '', 'excerpt' =&gt; '', 'blog_name' =&gt; '', 'charset' =&gt; '')</tt></dt>
<dd><p>Trackback data array.</p>
</dd></dl>

<dl class="attribute">
<dt>
<tt class="descname">$convert_ascii = TRUE</tt></dt>
<dd><p>Whether to convert high ASCII and MS Word characters to HTML entities.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::send">
<tt class="descname">send</tt><big>(</big><em>$tb_data</em><big>)</big><a class="headerlink" href="#CI_Trackback::send" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$tb_data</strong> (<em>array</em>) &#8211; Trackback data</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
</td>
</tr>
</tbody>
</table>
<p>Send trackback.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::receive">
<tt class="descname">receive</tt><big>(</big><big>)</big><a class="headerlink" href="#CI_Trackback::receive" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">TRUE on success, FALSE on failure</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
</tr>
</tbody>
</table>
<p>This method simply validates the incoming TB data, returning TRUE on success and FALSE on failure.
If the data is valid it is set to the <tt class="docutils literal"><span class="pre">$this-&gt;data</span></tt> array so that it can be inserted into a database.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::send_error">
<tt class="descname">send_error</tt><big>(</big><span class="optional">[</span><em>$message = 'Incomplete information'</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#CI_Trackback::send_error" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$message</strong> (<em>string</em>) &#8211; Error message</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
</td>
</tr>
</tbody>
</table>
<p>Responses to a trackback request with an error message.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">This method will terminate script execution.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::send_success">
<tt class="descname">send_success</tt><big>(</big><big>)</big><a class="headerlink" href="#CI_Trackback::send_success" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body">void</td>
</tr>
</tbody>
</table>
<p>Responses to a trackback request with a success message.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">This method will terminate script execution.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::data">
<tt class="descname">data</tt><big>(</big><em>$item</em><big>)</big><a class="headerlink" href="#CI_Trackback::data" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$item</strong> (<em>string</em>) &#8211; Data key</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Data value or empty string if not found</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Returns a single item from the response data array.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::process">
<tt class="descname">process</tt><big>(</big><em>$url</em>, <em>$data</em><big>)</big><a class="headerlink" href="#CI_Trackback::process" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$url</strong> (<em>string</em>) &#8211; Target url</li>
<li><strong>$data</strong> (<em>string</em>) &#8211; Raw POST data</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE on success, FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
</td>
</tr>
</tbody>
</table>
<p>Opens a socket connection and passes the data to the server, returning TRUE on success and FALSE on failure.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::extract_urls">
<tt class="descname">extract_urls</tt><big>(</big><em>$urls</em><big>)</big><a class="headerlink" href="#CI_Trackback::extract_urls" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$urls</strong> (<em>string</em>) &#8211; Comma-separated URL list</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Array of URLs</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">array</p>
</td>
</tr>
</tbody>
</table>
<p>This method lets multiple trackbacks to be sent. It takes a string of URLs (separated by comma or space) and puts each URL into an array.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::validate_url">
<tt class="descname">validate_url</tt><big>(</big><em>&amp;$url</em><big>)</big><a class="headerlink" href="#CI_Trackback::validate_url" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$url</strong> (<em>string</em>) &#8211; Trackback URL</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
</td>
</tr>
</tbody>
</table>
<p>Simply adds the <em>http://</em> prefix it it&#8217;s not already present in the URL.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::get_id">
<tt class="descname">get_id</tt><big>(</big><em>$url</em><big>)</big><a class="headerlink" href="#CI_Trackback::get_id" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$url</strong> (<em>string</em>) &#8211; Trackback URL</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">URL ID or FALSE on failure</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Find and return a trackback URL&#8217;s ID or FALSE on failure.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::convert_xml">
<tt class="descname">convert_xml</tt><big>(</big><em>$str</em><big>)</big><a class="headerlink" href="#CI_Trackback::convert_xml" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$str</strong> (<em>string</em>) &#8211; Input string</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Converted string</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Converts reserved XML characters to entities.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::limit_characters">
<tt class="descname">limit_characters</tt><big>(</big><em>$str</em><span class="optional">[</span>, <em>$n = 500</em><span class="optional">[</span>, <em>$end_char = '&amp;#8230;'</em><span class="optional">]</span><span class="optional">]</span><big>)</big><a class="headerlink" href="#CI_Trackback::limit_characters" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$str</strong> (<em>string</em>) &#8211; Input string</li>
<li><strong>$n</strong> (<em>int</em>) &#8211; Max characters number</li>
<li><strong>$end_char</strong> (<em>string</em>) &#8211; Character to put at end of string</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Shortened string</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Limits the string based on the character count. Will preserve complete words.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::convert_ascii">
<tt class="descname">convert_ascii</tt><big>(</big><em>$str</em><big>)</big><a class="headerlink" href="#CI_Trackback::convert_ascii" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$str</strong> (<em>string</em>) &#8211; Input string</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Converted string</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Converts high ASCII text and MS Word special characterss to HTML entities.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::set_error">
<tt class="descname">set_error</tt><big>(</big><em>$msg</em><big>)</big><a class="headerlink" href="#CI_Trackback::set_error" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$msg</strong> (<em>string</em>) &#8211; Error message</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
</td>
</tr>
</tbody>
</table>
<p>Set an log an error message.</p>
</dd></dl>

<dl class="method">
<dt id="CI_Trackback::display_errors">
<tt class="descname">display_errors</tt><big>(</big><span class="optional">[</span><em>$open = '&lt;p&gt;'</em><span class="optional">[</span>, <em>$close = '&lt;/p&gt;'</em><span class="optional">]</span><span class="optional">]</span><big>)</big><a class="headerlink" href="#CI_Trackback::display_errors" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>$open</strong> (<em>string</em>) &#8211; Open tag</li>
<li><strong>$close</strong> (<em>string</em>) &#8211; Close tag</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">HTML formatted error messages</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
</td>
</tr>
</tbody>
</table>
<p>Returns error messages formatted in HTML or an empty string if there are no errors.</p>
</dd></dl>

</dd></dl>

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